KR20060116148A - Method and system for planning the power of carriers in a cellular telecommunications network - Google Patents

Abstract

A method for planning carrier's power in a cellular communication network and a system thereof is provided to plan transmission power of each carrier with respect to determination made by a computing module such that power of a transmitter is shared with carriers of the same sector. A system for planning carrier's power in a cellular communication network comprises a data storage device(11), a transmitter carrier and a computing module(10). The data storage device(11) stores data(d1,d2,d3,d4) expressing features of a network. The transmitter carrier has a service region for distributing a traffic, to be processed at a sector(Sc), to N complementary regions(2) determined with respect to wireless attenuation. The computing module(10) offers a device for associating frequencies(f1,f2,f3) having their service regions(2).

Description

METHOD AND SYSTEM FOR PLANNING THE POWER OF CARRIERS IN A CELLULAR TELECOMMUNICATIONS NETWORK}

1 is a schematic diagram of a data processing system of the present invention, showing a portion of a network showing the distribution of transmit power between various service areas of a transmission sector.

2 shows an example of power distribution among several service zones for a total transmit power of 40W.

3 is a graphical representation of traffic distribution in a transmission sector with respect to transmission and reception attenuation in the sector.

4 is a flowchart of the steps of the method according to one embodiment of the present invention.

5 is a geographic map showing traffic distribution used in the power sharing method of the present invention to allow an equal distribution of traffic between carriers of each transmission sector as an example of the data processing system of the present invention.

TECHNICAL FIELD The present invention relates to a cellular mobile wireless network, and more particularly, to a method and system for adjusting the power of a carrier in a cellular communication network, for the purpose of improving the wireless coverage and user bit rate of a network managed by an operator. will be.

The cellular mobile radio network consists of a plurality of radio base stations provided with transmitters to ensure radio coverage of the area defining each cell. In a wireless communication system, each base station communicates with a plurality of remote terminals, such as cellular cellular telephones. Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) are conventional multiple access layouts that allow for simultaneous service to any number of terminals. The basic idea of FDMA or TDMA is to divide the available resources into several frequencies or time divisions so that multiple terminals function simultaneously without interference.

Telephone operation under the GSM standard (GLOBAL System for Mobile Communications), which belongs to the FDMA and TDMA schemes for transmission and reception, is performed at different frequencies and at different time intervals.

Unlike these schemes using frequency division or time division, the Code Division Multiple Access (CDMA) scheme allows multiple users to share a common time channel and common frequency using coded modulation. The use of spectrum-spread CDMA technology provides high data rates for mobile terminals. The most recent so called third generation (3G) CDMA standard (e.g., wideband CDMA: W-CDMA) is being released for many operators. Examples of the CDMA system include the CDMA 2000 system, the W-CDMA system ("wideband CDMA"), or the IS-95 standard.

The CDMA scheme uses a separate frequency for transmission and reception (CDMA-FDD scheme) and a common frequency for transmission and reception, but a separate time domain for transmission and reception (CDMA-TDD). Method). In a CDMA type system, a network architecture using an IP protocol (Internet Protocol) is used to provide a high speed packet to a downlink shared channel (DSCH channel) via wireless access of a high-speed downlink packet access (HSDPA) type. To transmit data. HSDPA mode increases coding efficiency over conventional UMTS mode, which allows for increased data rates. Similar to the HSDPA technology specified by the third generation partnership plan (3GPP), other radio access technologies that use multiple channels, especially CDMA 2000 1xEvDO (Evolution Data Only) technology, to achieve high data rates. This exists. For the sake of indication, the HSDPA standard has been specified to provide high capacity and high speed transmission (up to 14 Mbps) for existing W-CDMA networks and should provide improved service quality and desirable cost / performance ratios for both operators and subscribers. According to this type of technology, the operator can provide a large amount of high-speed data to the subscriber at the same radio frequency (carrier) and can guarantee the subscriber the optimal service of the present or future multimedia service.

The present invention relates to a CDMA type network, more broadly, a radio access technology requiring multiple DSCH channels each using a radio frequency called a carrier, all cells using the same radio frequency with constant transmission power, coverage of each frequency. Applies to networks using wireless access that do not require continuity. Thus, the present invention provides data access, as defined and specified by 3GGP, in particular HSPDA, CDMA 2000 1xEvDO, which provides the additional capacity needed to meet the growing demands of the mobile phone market in terms of high speed mobile applications such as downloading content. Technology and similar data access technology (without circuit switched voice transmission).

A method from the document WO 2005/011154 is known which is set up to prevent a reduction in the data rate for the user in the 1xEvDO scheme. However, this method relates only to connection problems at the base station and proposes management of user-associated connections to avoid overloading these connections.

In CDMA type cellular mobile telephone systems using multiple carriers, there is no way to optimize the capacity of the network, in particular by limiting the cumulative transmission output to the user's portable terminal to operatively adapt to the traffic to be processed. Existing solutions are limited for output regulation in each cell, which is not satisfactory from an operational point of view because the load variation is in one and the same cell.

One major drawback of the known method is that certain areas within one cell do not provide good radio access due to too low signal to noise ratio (SNR). In these areas, the data rate is very low (for a given bandwidth) or the use of a very wide channel is required to ensure a sufficient bit rate.

For illustration, the output ratio C / I between the carrier signal and the interference signal may vary from 0 to 15 dB or more depending on whether the customer using the cellular phone is near the edge of the cell or near the transmitter. Current solutions for increasing network capacity include adding new carriers on additional frequencies, and the channeling of CDMA type technology is fixed (channel width of 1.25 MHz for CDMA 2000 and 5 MHz for UMTS). width).

Therefore, there is a need to find a way to adapt to the running conditions that can efficiently configure the network to optimize the data rate and overall capacity of the network for users located in the worst served cell region.

It is an object of the present invention to provide one or more disadvantages of the prior art by defining a power regulation method in which a CDMA type cellular communication network can provide an optimized effective bit rate at every point of a cell.

It is a further object of the present invention to provide a method for each radio base station used for radio access to data by high speed packet transmission technology (3GGP: HSDPA CDMA 2000 1xEvDO, etc.) when the power is shared between different frequencies (broadband power amplifier). Optimizing the use of available power in the amplifier.

For this purpose, the present invention allows the reuse of one and the same frequency for all cells of a network (e.g. of CDMA type access) provided with a wireless base station having a transmitter for transmitting data towards a given transmission sector A method for adjusting carrier power in a cellular wireless communication network having a characteristic of securing wireless coverage of an area defining a cell, the method comprising: a geographical area divided into a plurality of dots or pixels per divided part of the network; Data processing provided with storage means for storing data representing an area, characteristic data of the network sector and transmitter, data representing transmit / receive radio attenuation for each sector, and data representing the amount and distribution of traffic in the network. Is carried out via a system, the method comprising: a data processing system The computing module 10 of (1) assigns a carrier to the service area 2 for each transmission sector Sc associated with the transmitter TR having a plurality of carriers C1, C2, CN-1, CN. An assignment step 42 is made to assign, and the computing module 10 is configured to N total traffic TF to be processed in the sector Sc in N complementary service zones 2 determined with respect to radio attenuation. Using the data (d1, d2, d3, d4) stored in the storage means 11 to distribute to the shared traffic TF / N and also forming rings gradually away from the transmitter TR, the method Also,

A frequency adjustment step comprising allocation of a predetermined frequency for each service zone such that different carriers used in the sector are each associated with a single service zone of the sector;

And, for each service zone, the power adjustment step for each of the carriers, including, for each service zone, a determination of the signal-to-noise ratio in each pixel and the traffic processing capability of the carrier associated with the service zone. The allocation of transmit power between carriers of one and the same sector is determined and determined by the computing module so as to correspond to obtaining a maximum for the sum of traffic processing capabilities by the carrier for each sector, the maximum being especially And a power adjustment step resulting from at least one comparison by the computing module between several separate solutions for allocating power therebetween.

Accordingly, the present invention can adjust the power of each carrier separately for the traffic to be covered.

According to another feature, allocation of transmitter power between carriers of one and the same sector is assigned to the computing module such that the power adjustment step corresponds to obtaining a maximum variance of the traffic processing capability provided separately by different carriers of the sector. It is done in a manner determined by.

According to another feature, the service zone is determined in a sector with respect to an attenuation threshold, wherein the first service zone groups together pixels whose attenuation of transmit / receive radio signal propagation is lower than a first predetermined threshold, and wherein at least one first The two service zones group together pixels whose attenuation of the transmit / receive radio signal propagation is between the first predetermined threshold and the predetermined maximum attenuation.

Thus, according to the present invention, a particular carrier can be used to provide to a service area away from the transmitter. Carriers associated with the distanced service areas may be preferably transmitted at higher power to ensure a data rate comparable to the rate supplied in the vicinity of the transmitter by carriers with weaker transmit power.

According to another feature, the method comprises the step of setting the following parameters:

A list of sectors and the available power characteristics of these sectors,

A matrix of propagation attenuation for each sector,

A matrix of traffic distribution,

A coefficient of usage indicating the amount of traffic,

Specification of the number of carriers per sector,

A matching rule for associating a carrier with the transmit amplifier,

A prediction parameter for use in at least one convergence function used to verify that said power adjustment corresponds in particular to obtaining a maximum for the sum of the traffic processing capabilities of the carriers of all sectors.

According to another feature, data indicative of the amount and distribution of traffic in a network includes data and geographic area indicative of traffic in a subscriber's network to the network, including a measure of the quantity and quality of the subscriber traffic on the network. And a map of traffic distribution made through a data processing system using data indicative of said data, said measurement corresponding to at least one predetermined time slot, wherein at least one map of traffic distribution in said network is associated with a user. After selection of at least one geographic area via means of interaction between said data processing systems and retrieval of said system of data indicative of traffic corresponding to said selected geographic area and a given time slot. The use of data items by the processing system makes it possible to generate data indicative of coverage of cells associated with each transmitter.

According to another feature, the data representative of the traffic in the wireless communication network includes data supplied by counting means and extracted from at least one operation and repair center by means of extraction and table means of the data processing system.

According to another feature, the allocation step of allocating a carrier to a service area is processed by a calculation step to calculate traffic distribution in an area corresponding to network coverage, and this traffic distribution calculation step is performed in each pixel. Using the traffic distribution map to predict the traffic and through the data representing the transmit and receive radio attenuation for each sector, the assignability and contiguity for the sector with respect to the received field and the attenuation between the transmitter and receiver in the sector under consideration Consider the reception level of the sectors.

According to another feature, the traffic distribution calculating step includes a calculation of the cumulative distribution function of the traffic to be processed with respect to the level of propagation attenuation in each sector under consideration.

According to another feature, the assigning step of allocating carriers to a service area for at least one of the sectors includes calculating the total traffic to be processed and determining the number of sufficient carriers N so that the capacity of all carriers in the sector is total. Allow traffic to be handled

According to another feature, the frequency adjustment step is processed by a calculation step for calculating interference constraints between carriers, including the calculation of a compatibility matrix between all carriers in all cells.

According to another feature, the power adjustment step for each carrier in all sectors is individually by different carriers of each sector and the first criterion corresponding to obtaining a maximum of the sum of the traffic processing capability of the carrier of the sectors. And a first prediction step of predicting convergence between second criteria corresponding to obtaining a minimum variance of the provided traffic processing capability.

According to another feature, following the power adjustment step, a calculation step is performed to calculate a new frequency constraint resulting from the power adjustment, followed by a second prediction step of predicting convergence between the first and second criteria.

According to another feature, the method comprises a third prediction step for predicting the convergence between the first criterion and the second criterion, performed immediately after a new calculation step of the service zone of each carrier, wherein the new calculation step Takes into account the variation resulting from the power adjustment in particular.

According to another feature, at least one calculation of the convergence function in a form corresponding to a difference between a first value representing the first criterion and a second value representing the second criterion, and then to an acceptable convergence The allowable threshold which is not exceeded is compared with the variation in the difference.

According to another feature, repetition of transmission outputs shared between carriers of one same sector is initiated when an acceptable threshold is exceeded in the first prediction step of convergence between the first criterion and the second criterion.

According to another feature, the repetition of the calculation step of the interference constraint between the carriers and the frequency adjustment step is triggered when an allowable threshold is exceeded in the second prediction step of convergence between the first criterion and the second criterion.

According to another feature, the repetition of the step of assigning carriers to the service area is triggered when the tolerance threshold is exceeded in the third prediction step of convergence between the first criterion and the second criterion.

Accordingly, the present invention has the advantage of enabling optimal sharing of power between carriers on one and the same transmitter according to the two criteria, which is particularly true for service zone prediction that is made during the allocation step of allocating carriers to the service zone. By using a repeating loop for, it applies to all transmitters in the network.

It is another object of the present invention, in particular for the optimal use of available power in multi-carrier amplifiers (broadbands), especially in HSPDA and CDMA1xEvDO, by defining a data processing system which is particularly suitable for the method of the present invention. It provides a solution to the problems.

The object is data representing a geographic area divided into a plurality of dots or pixels according to the division of a computing module and the network, data representing characteristics of the network sector and the transmitter, and data representing transmit / receive radio attenuation for each sector. Is achieved by a data processing system for implementing the method of the present invention comprising storage means for storing data indicative of the amount and distribution of traffic in the network, the system comprising a respective transmission sector Sc associated with a transmitter TR. Selection means 12 for selecting), wherein the computing module comprises:

Associate the transmitter carrier with the service zone using the data stored in the storage means to distribute the total sector traffic processed across the N shares of traffic to the N complementary service zones determined for radio attenuation,

Association means for associating a predetermined frequency with each service zone such that different carriers used in one sector are each associated with a single service zone of the sector,

The data processing means comprises means for adjusting the transmit power of each carrier in connection with a determination made by a computing module for sharing transmit power between carriers of one and the same sector.

According to another feature, the computing module is configured to provide, according to a first criterion, a maximum for the sum of the traffic processing capacities of the carriers of all sectors and, according to a second criterion, the traffic processing capacity individually provided by the different carriers of the sector. The transmission power is shared between carriers of one and the same sector using a suitable optimal program to obtain the minimum variance, and the prediction parameters stored in the storage means are used by the computing module to allow optimization of the transmitter power shared between the carriers. Do it.

According to another feature, the associating means is arranged with consideration of an attenuation threshold to determine a service zone of a sector, wherein the associating means has a transmit and receive radio signal propagation of attenuation lower than a first predetermined threshold in the first service zone. Pixels and, in the second service zone, attenuation of the transmit and receive radio signal propagation group the pixels together between the first threshold and a predetermined maximum attenuation.

According to another feature, the system includes a data memory representing traffic data in the network in at least one predetermined time slot, the system further comprising:

Means for interacting with a selection means to select and display at least one said geographical area, said means for interaction between a user and said system,

Overlapping means for superimposing data representing the traffic in a predetermined time slot on the selected geographic area to form at least one map of traffic distribution indicated by the interaction means,

Extraction and tableing means for using the data supplied by the computing means from at least one operational and repair center and for extracting and tableing a series of measurements with respect to the geographical area and time slots.

BRIEF DESCRIPTION OF THE DRAWINGS The invention having the above features and advantages will become more apparent by the following detailed description with reference to the accompanying drawings provided as non-limiting examples.

Referring to Fig. 1, a power adjustment tool for optimizing the cellular communication network N is, in particular, associated with each transmission sector associated with the transmitter TR of the computing module 10, the storage means 11 and the transmit / receive base station BTS. Selection means 12 for selecting Sc) are provided with the data processing system 1 provided. In a preferred embodiment of the present invention, the storage means 11 includes first data d1 representing a geographical area divided into a plurality of dots of pixels 301, 302 and 303 (see Fig. 5) according to the division of the network, and the network. Second data d2 indicating characteristics of the transmitter TR and sector Sc of (N), third data d3 indicating transmission / reception radio attenuation for each sector Sc, and network N; Store the fourth data d4 representing the amount and distribution of traffic.

In a known manner, when setting the coverage of the wireless communication network N, the cells are set up to ensure continuity of this coverage. According to the invention, the coverage area of each transmitter TR is calculated using a predictive model associated with a database d1 that represents a geographic area and in particular contains appropriate land survey and topographic information. The attachability to each transmitter TR is calculated at each dot or pixel 301, 302, 303 of the area under consideration, thereby defining the geographical transmission sector Sc for each transmitter TR. By controlling the radio frequency used by a given transmitter, it minimizes interference (by minimizing the interference ratio C / I for the carrier) and maximizes the bit rate at each point 301, 302, 303.

Traffic mapping may be associated with probabilities at each access point for each cell to accurately define the predicted traffic inside each cell. The data processing system 1 is used, for example, when setting up a target wireless network in a geographical area and allows different traffic maps to be drawn. The traffic information obtained by the existing network is used to predict the proper setting of radio coverage.

Referring to Fig. 5, on the interaction entry and display device 3 of the data processing system 1, a graphical representation of the map 30 is presented in a wireless communication circuit in a geographic area in which a target network is determined. By providing traffic distribution (traffic data only). The map 30 schematically shows the superposition of the initial data from the digital map and the data representing the traffic on the wireless communication circuit of the network subscriber firstly, and these data items are stored in the storage means 11, for example. do. The central or similar form of the computing module 10, the storage means 11, the data input means using a mouse and the data providing means on a keyboard or other device and the interactive screen 3 are not shown in detail.

Data indicative of traffic in the wireless communication circuit is extracted from at least one Operation and Repair Center (OMC) by extraction and tableing means 15 supplied by the counting means 4 and used by the data processing system 1. Contains data that is This extracted data may consist of average traffic measurements taken at different points in the geographic area under consideration or several series of quantity and qualitative traffic measurements. Each series of measurements corresponds, for example, to different time slots for one and the same location. In one embodiment of the present invention, extraction and table means are used to classify the measurements in relation to the geographic map and the time slot. In a non-limiting example of a UMTS network, the unit of measure for traffic is cell units.

In one embodiment of the invention, data on the current traffic is provided by a counting means 4 of the performance analysis (APIC) type using indicators and counters. This counting means 4 can store the counters of the OMC center for several weeks and provide complex indicators according to the trend of these counters. A tool in the form of APIC can be used, for example, to ensure extraction of counters at the National level from other OMC centers. These measurements are, for example, average values calculated from measurements taken at every dot or pixel over a week and are grouped together in a database accessible by the system 1 in the form of a file or traffic table.

In the embodiment shown in Fig. 5, the pixels 301, 302, 303 are used for identifying color or graphic shadows or the like for each traffic level value tlv expressed in mE / km ² or equivalent units of traffic representing the occupancy of radio resources. To combine. For example, pixels 301 corresponding to traffic between 10000 and 30000 mE / km ² are displayed in warm shades in warm shades, and pixels 302 corresponding to less traffic greater than 500 mE / km ² are slightly warm in color. And the pixel 303 for low traffic is shown in a different color. In a non-limiting state, it is desirable that the nearest grading of the traffic level value tlv be considered to make a good analysis of the network N.

The traffic analysis map 30 obtained as described above has the advantage of being independent of the wireless communication system or infrastructure used and its corresponding cellular network, allowing for effective prediction of traffic for system changes. Additional carriers should be added as the traffic requires. For example, some sectors Sc with high traffic (FIG. 1) are provided with carriers C while a single carrier may be sufficient for other sectors corresponding to low traffic areas.

Once the number of transmitters TR is determined, the system 1 of the present invention can be advantageously used to control the frequency f and power P of each carrier C in each transmission sector Sc. . Referring to FIG. 1, the computing module 10 uses the data d1, d2, d3, d4 stored in the memory means 11 to support the carriers C1, C2, CN-1, An association means for matching the CN with the service zone 2 is provided, which serves to distribute the entire traffic TF of the sector Sc to the service zone 2 fairly and appropriately. In other words, the system is configured to match each carrier C with the service area 2 in an optimized manner, such that each carrier C is equal to the total traffic TF processed in the sector Sc. It is supposed to take charge of minutes (TF / N).

Referring to Fig. 3, the service area 2 may be divided in relation to thresholds S1 and S2 of transmit and receive radio signal attenuation. This is actually done by dividing into geographical rings for the service areas 21, 22, 23, as shown in FIGS. 1 and 2. In the example shown in FIG. 3, the associating means of the computing module 10 is configured to calculate the total traffic TF processed in the sector Sc in N complementary service zones 2 (determined with respect to radio attenuation). It is guaranteed to be split into N shared traffic (TF / N). In addition, the associating means associates the predetermined frequencies f1, f2, and f3 with the respective service areas 21, 22, and 23, so that different carriers C used in one sector Sc are each said. Corresponds to the single service zone 2 of the sector Sc. The boundaries of the rings are determined per sector Sc in relation to the attenuation thresholds S1 and S2 (see Fig. 3). For example, the first service zone 21 groups pixels whose attenuation of transmit and receive radio signal propagation is lower than a predetermined first threshold S1, while at least one of the second service zones 22, 23 transmits and receives. Group the pixels whose attenuation of radio signal propagation is between the first threshold S1 and a predetermined maximum attenuation Max.

The data processing system 1 according to the invention transmits power such that each carrier C is responsible for the traffic being processed for the geographical ring (bounded by the respective power of the adjacent carrier and / or the carrier at the same location). It includes a means 13 for adjusting the. The system 1 can calculate the power threshold within one same sector Sc and between carriers C of one same sector Sc, as determined by the computing module 10. It has means 13 for adjusting the transmit power of each carrier C in connection with the share of transmit power.

The redirection of each user wireless terminal to one of the frequencies of one and the same sector Sc is a network parameter, the difference in the received field level between the frequencies of the sector Sc, or the different in the sector Sc. It is managed by the data processing system 1 in relation to the load of frequencies. The optimization achieved by the system is related to the downward flow from the base station (BTS) to the wireless terminal because the traffic data is highly asymmetric.

The power regulation method is described in more detail with reference to FIGS.

The method of the present invention is applied to a cellular wireless communication network N of CDMA access type and requires an initialization step 40. During this initialization phase, the system 1 sets the configuration parameters of all the problems to be solved. In particular, set the following:

A list d2 of sectors Sc and their available power characteristics;

Matrices of propagation attenuation d30 for each sector;

A matrix of traffic distribution d41;

A usage factor indicating the traffic amount d42;

A specification d22 for the number of carriers per sector;

A matching rule d23 for associating a transmitter amplifier with a carrier; And

An evaluation parameter for use in at least one convergence function (TEMP) used to confirm that the power adjustment corresponds to obtaining a maximum value for the sum of the traffic processing capacity of the carriers C in all sectors Sc. (d5).

An operation step 41 of calculating the traffic distribution in the area corresponding to the coverage of the network N is performed first, followed by optimization by adjusting the power of each transmitter TR. The computational step 41 for this traffic distribution uses a traffic distribution map to evaluate the traffic at each pixel and considers it via data d3 representing transmit and receive radio attenuation for each sector Sc. Consider the attenuation (Si) between the transmitter and the receiver in the sector in question, and the possibility of allocation to that sector in relation to the reception field and reception level of the adjacent sector.

Traffic may be directed towards any of the carriers associated with a particular algorithm mode using the Radio Resources Management (RRM) tool of the radio access technology. For example, it may be selected based on a criterion according to the reception field level for the reference threshold. In an initial stage, the traffic distribution associated with the estimated propagation attenuation between the transmitter TR and each point may be defined for each sector of each base station (BTS) as shown in FIG. For each basic coverage area and each sector Sc, represented by pixels 301, 302, 303 with coordinates "x, y", the method uses:

The "pathloss" attenuation between the transmitter and the receiver in the considered sector, where ρpath (x, y) = 1 if pathloss (x, y) = PATHLOSS and ρpath (x, y) = 0),

The path probability (sector, x, y) for allocation to sector Sc in relation to the reception field and reception level of the adjacent sector, the probability computed in terms of the standard deviation from the prediction model,

Traffic evaluated at "traffic (x, y)" which is a point derived from the traffic mapping in the area under consideration.

 The pathloss (x, y) function corresponds to the radio attenuation associated with the distance from the transmitter TR. Such a function may be specified by, for example, a formula obtained by using a propagation parameter or a formula obtained by correcting a parameter list, and may carry an overall value called PATHLOSS at every point where there is traffic. Thus, this function provides the PATHLOSS attenuation values used to allow traffic distribution within the sector Sc. According to the present invention, by scanning all PATHLOSS values for each sector Sc, it accumulates for the traffic to be processed in relation to the PATHLOSS attenuation in the sector under consideration as shown in FIG. The distribution function is obtained.

In the example of Fig. 3, the attenuation thresholds S1 and S2 are intended to equally divide the traffic request into N equal shares. The number N of carriers C1, C2, CN-1, CN in the sector Sc can be specified directly by the user of the system 1 or calculated via the computing module 10 of the system 1. have. In the latter case, the total traffic TF in sector Sc integrates the distribution function shown in Figure 3 for all PATHLOSS attenuation values and represents the usage coefficient specified by the user (amount of traffic). Can be calculated by multiplying Therefore, the total traffic TF of the sector Sc is obtained by the following equation.

The associating means of the computing module 10 determines the number N of necessary carriers C obtained by dividing the total traffic TF by the capacity of each carrier parameterized by the user. In one embodiment of the invention, a warning message is displayed by the interactive device 3 when the number of required carriers exceeds the number of available radio frequencies.

Referring to FIG. 4, the computing module 10 performs an allocation step 42 of allocating carriers to the service area 2 in consideration of the number N of carriers C determined for each transmitter TR. Run The attenuation thresholds S1 and S2 used to equally divide the total traffic TF processed into N equal shares (TF / N) are associated means of the computing module 10 for dividing the service area 2. Is computed by Thus, during this allocation step 42, the computing module 10 causes the overall traffic TF to be processed to be geographically separated from the transmitter TR as shown in FIGS. 1 and 2 and radio attenuation. Guarantees distribution to the N complementary service areas 2 determined in relation to. In order not to cause problems in the service area 2 away from the transmitter, the method of the present invention advantageously proposes assigning high power to these remote areas.

However, power coordination should be optimized for the best use of the radio resources of the network N. In a preferred embodiment of the present invention, the computing module 10 shares the transmission power between the carriers C of one same sector Sc by an optimization program, which program according to the first criterion. Obtain a maximum value of the sum of the traffic processing capacities of the carriers C in Sc, and determine the minimum deviation of the traffic processing capacities individually provided by different carriers C in the sector Sc according to the second criterion. It is supposed to get. The evaluation parameter d5 stored in the memory means 11 can be used by the computing module 10 for optimized sharing of the transmit power between the carriers C.

1 and 4, the power adjustment is made only after the frequency adjustment step 44, which assigns predetermined frequencies f1, f2, and f3 to the respective service zones 21, 22, and 23. Thereby allowing each of the different carriers C used in the sector Sc to correspond with a single service area of the sector Sc. If the appearance of the coverage zone is determined by the division of the service zone 2, the frequency adjustment steps 43, 44 are for example EP 1 283 647 (or corresponding US Patent Publication 2003/07805). It should be disclosed in the same or similar manner for GSM in accordance with the disclosure in. An operation step 43 for computing the interference limit between carriers C is performed using the conformance matrix between all carriers C of all cells. The system can be parameterized to mark different carriers C of sector Sc to be mutually exclusive with respect to the assignment of radio frequencies. Since the present invention is applied to data exchange techniques such as 3GPP, HSDPA and CDMA 2000x1xEvDO, which allows a reuse factor of 1 for frequencies, interference effects by adjacent frequencies can be neglected so that frequency adjustment steps 43 and 44 can be avoided. It is possible to facilitate. The actual frequency adjustment step 44 takes place sequentially. This step is easier than with GSM, since the number of frequencies is much smaller in CDMA type systems (channels with a wide channel width, for example 1.25 or 5 MHz wide).

The result of the frequency adjustment step 44 is then used to calculate a map of signal to noise ratio (SNR) at all points and for all carriers C as follows.

Then, the traffic that can be handled by the carrier, or the capacity of the carrier C, can be evaluated in relation to the power allocated to each carrier of the transmitter TR. According to the invention, this capacity is determined using the discrete function Perf (SNR) set by the user in relation to the nature of the radio access technology.

By default, the Shannon-Hartley formula can be used:

Where W corresponds to bandwidth (Hz), SNR is the signal-to-noise ratio (considering white Gaussian noise), and Perf (SNR) is the capacity or rate (by the transmitter) (bit / s).

The traffic processing capacity in sector Sc is the sum of the traffic that can be handled by each carrier C1, C2, CN-1, CN of the sector, and this traffic processing capacity is calculated as follows:

;i는 1부터 N사이임.

; i is between 1 and N

Thus, the power adjustment step 45 can be executed for each carrier C. As described above, the power adjustment step 45 determines the signal-to-noise ratio at each pixel for each service zone 2 and then determines the traffic processing capacity of the carriers C in the service zone 2. do. Therefore, the step consists of sharing the transmission power between carriers of one same sector Sc. This sharing can be performed as determined by the computing module 10 to obtain a maximum of the sum of the traffic processing capacities of the carriers C in all sectors Sc. In addition to the first criterion, an equal share of traffic should be made between service areas (2). For this purpose, a second traffic coordination criterion between each carrier C of one same sector Sc is considered.

Sharing is possible by adjusting the transmitter TR of the base station BTS. The broadband power amplifier makes it possible to transmit different power signals for the various carriers C by sharing the amplifier power. The adjusting means 13 of the data processing system 1 are designed to allow adjustment of such power sharing. With unequal power distribution between each transmission channel, it is possible to optimize the wireless coverage defined by the carrier CN with the maximum power. As shown in Fig. 2, the unequal power distribution between the various service zones 2 in the sector Sc results in the distribution of data in the farthest zone (and therefore the largest radio attenuation) at a very good data rate. This enables transmission, by allocating most of the total power to the carrier (CN) associated with the zone that forms the final geographic ring. In a sector Sc with three service zones as shown in Fig. 2, if the amplifier has a power of 40W for example for wireless transmission, 30W of power P2 is responsible for the area forming the last ring. The power P1 of 2W may be allocated to the carrier C2 (frequency f2), and the power P1 of 2W may be allocated to the carrier C1 (frequency f1) that is closest to the transmitter TR and is responsible for the service area corresponding to the first ring.

The adjusting means 13 of the system 1 share the power with special consideration given to the following information (these parameters are set by the user):

The power of the amplifier responsible for the carrier C; And

A list of different carriers C which are amplified by the same amplifier.

Referring to FIG. 4, the adjusting step 45 for adjusting the power P1, P2, P3, P1 ′, P2 ′, P3 ′ of each carrier C is finally performed for each sector Sc. Traffic separately provided by the reference (corresponding to a maximum value of the sum of the traffic processing capacities of the carriers C of all sectors Sc) and the second reference (different carriers C of sectors Sc) And a first evaluation step 46 of evaluating convergence between the minimum deviations of the processing doses). This convergence evaluation step 46 includes calculation of the convergence function TEMP (parameters set by the user). This convergence function TEMP may correspond to the difference between a first value representing the first criterion and a value representing the second criterion. The tendency in this difference is computed by determining the deviation of the difference between the parameterized number Xi for successive operations of the TEMP function, for example, to take into account power distribution changes, and then this tendency Is compared with the acceptance threshold Xa not exceeded for acceptable convergence. As an illustrative example, the calculated trend when Xi = 1 corresponds to the deviation between two consecutive operations. Repetition R1 for the sharing of transmit power between carriers C of one same sector Sc is such that the deviation during the first convergence evaluation step 46 between the first and second criteria is increased. It starts when it exceeds the accommodation threshold Xa.

In one embodiment of the invention, the convergence function TEMP is defined as follows.

는 각 섹터(Sc)의 용량들의 합계이며, 용량(Sc)/N_섹터는 N개 캐리어들에 대한 섹터(Sc)내의 캐리어들의 평균 용량이다. Wherein Cr1 and Cr2 are the weights of the first criterion and the second criterion, respectively,

Is the sum of the capacities of each sector Sc, and the capacity Sc / N _sector is the average capacity of the carriers in the sector Sc for the N carriers.

This convergence function TEMP is calculated for each basic deviation in the power of the carrier C, for example, but the limitation of each amplifier is observed. Referring to Figure 4, a first convergence evaluation step 46 for the two criteria is performed to optimize the power sharing, which optimization uses a method based on a simulated "annealing" technique. Two parameters, the acceptance threshold Xa and the number of repetitions Xi, can be set by the user so that the optimization is performed until the deviation in the convergence function TEMP over Xi iterations is lower than the threshold Xa. Will be done. The solution corresponding to the highest value for the convergence function TEMP is maintained. The value of this TEMP function corresponds to the difference between a first element representing global capacity and a second element representing inconsistency in the capacities of carriers C in each sector Sc. . Therefore, this value becomes higher as the global capacity becomes larger (a first criterion with a Cr1 weight), and traffic in the sector Sc is equally distributed among the service areas 2 (the second with a Cr2 weight). Criteria) will be understood.

If the result of power sharing causes a change that causes the frequency adjustment steps 43 and 44 to be in a sub-optimized state, the frequency adjustment must be redone with new power due to the power change in the transmitter TR. Thus, as shown in Fig. 4, the power adjustment step 45 is followed by a calculation step 47 for calculating a new frequency limit resulting from the power adjustment. A second convergence evaluation step 48 between the first criterion and the second criterion is performed, where the repeated number Xi and the acceptance threshold Xa parameterized by the user are used. According to the same principle as in the first evaluation step 46, the computing module 10 selects a solution that can obtain the highest value for the convergence function TEMP among different solutions (stored in the system).

While the repeated number Xi is not reached, the first evaluation step 46 automatically returns to the power adjustment step 45 without selecting a solution. When the repeated number Xi is reached and exceeded, a comparison of the deviation between the acceptance threshold Xa and the trend in the convergence function TEMP is made. If the deviation in the TEMP function exceeds the threshold value Xa over the Xi period, it is determined that there is no convergence and triggers the repetition of power sharing R1.

Similarly, following the second convergence evaluation step 48 between the first criterion and the second criterion, an iteration R2 of the preceding steps 43 and 44 is performed to limit the interference between the carriers C. Compute and control the frequencies while the deviation in the TEMP function over the Xi 'period exceeds the acceptance threshold Xa'. In practice, Xi '= 2 may be selected in consideration of the small number of frequencies, and satisfactory results may be obtained after several iterations for step 43 for calculating the limit. Thus, if the deviation in the TEMP function over the iterations of Xi '= 2 is less than the acceptance threshold Xa', then the second evaluation step 48 may be declared to be positive. It is clear that Xi '= 1 can be taken, and values greater than 2 are possible.

Referring to Fig. 4, the solution allowing to obtain the highest value for the convergence function TEMP obtained after the second evaluation step 48 is in a new calculation step 49 for calculating the service zone 2 of each carrier C. Used. This new computational step 49 specifically takes into account changes resulting from previous power adjustments. A third evaluation step 50 follows to evaluate the convergence between the first criterion and the second criterion according to the same principles as for the previous two evaluation steps 46, 48. The acceptance threshold Xa "and the repeated number Xi" are parameterized by the user to ensure convergence as and when the convergence function TEMP diverges.

While the deviation in the TEMP function over the Xi " period exceeds the acceptance threshold Xa ", the carrier C must be assigned following the third convergence evaluation step 50 between the first and second criteria. This is followed by a repetition R3 of the evaluation step 42 of evaluating the service zone 2. In fact, considering a small number of frequencies (for GSM), a small number of iterations converge to a satisfactory result. If the third evaluation step 48 is declared positive, the parameters corresponding to the optimized solution are retained and stored during the processing termination step 50.

Thus, during the termination step 50, the data processing system 1 retains the following optimization parameters:

The number of carriers C;

The frequency used for each carrier C;

Power for each carrier C; And

Threshold of the received power for each carrier C, for carrier selection between different carriers of the sector Sc.

One of the advantages of the present invention is the problem of service zones with late transmission rates ("soft handover" limitation) in third generation data transmission systems (does not require access to two cells of the same frequency). To provide an optimal solution. The present invention relates to providing the possibility of maximizing the capacity of the network (N) by adjusting the power of each carrier (C) for efficient handling of the total traffic and to providing an optimized transmission rate in all parts of the coverage area. will be. In addition, this type of solution allows development adaptability in network capacity requirements through non-uniform power distribution between carriers (C). This distribution is economical because it requires little dependence on additional amplifiers for data transmission.

It will be apparent to those skilled in the art that the present invention is capable of many other specific forms of embodiment without departing from the scope of the claimed invention. Accordingly, the described embodiments should be considered as examples, which may be modified within the scope defined by the appended claims and the invention is not to be construed as limited to the foregoing detailed examples.

According to the present invention as described above, it is possible to solve one or more disadvantages of the prior art by defining a power adjusting method in which a CDMA type cellular communication network can provide an optimized effective bit rate at every point of a cell.

Claims (21)

A radio base station (BTS) having a transmitter (TR) for transmitting data to a given transmission sector Sc allows for reuse of one and the same frequency for all cells of a network (e.g. of CDMA type access) and also each A method for adjusting carrier power in a cellular wireless communication network (N) having a characteristic of securing wireless coverage of an area defining a cell of the cell, the method comprising: a plurality of dots or pixels 301 according to division of the network; Data d1 representing a geographic area divided into 302 and 303, data characteristics d2 of a sector Sc and a transmitter TR of the network, and a transmission / reception radio attenuation for each sector Sc. A data processing system 1 is provided via a data processing system 1 provided with a storage means 11 for storing data d3 and data d4 representing the amount and distribution of traffic in a network. The computing module 10 of the system 1 carries a carrier to the service area 2 for each transmission sector Sc associated with the transmitter TR having a plurality of carriers C1, C2, CN-1, CN. Assigning step 42, the computing module 10 calculates the total traffic TF to be processed in the sector Sc in the N complementary service zones 2 determined with respect to radio attenuation. Use the data (d1, d2, d3, d4) stored in the storage means 11 to distribute to N shares of traffic TF / N, and also form rings gradually away from the transmitter TR, and The method also, Assignment of predetermined frequencies f1, f2, f3 to each service zone 21, 22, 23 so that different carriers C used in sector Sc are respectively associated with a single service zone of the sector Sc. A frequency adjusting step 44 which includes; The computing module 10 also determines, by the computing module 10, for each service zone 2, the signal-to-noise ratio in each pixel and the carrier (C traffic handling capability of the carrier C associated with the service zone 2). Power adjustment step 45 for each of the carriers comprising: such that the power adjustment step 45 corresponds to obtaining a maximum for the sum of the traffic processing capabilities of the carrier C for each sector Sc; Allocation of the transmission power between the carriers of one and the same sector Sc is determined by the computing module 10 and the maximum is in particular several separate solutions for allocating power between the carriers C. A power adjustment step (45) resulting from at least one comparison by said computing module (10) between them. 2. The same sector Sc as claimed in claim 1, wherein the power adjustment step 45 corresponds to obtaining a maximum variance of the traffic processing capability provided by the different carriers C of the sector Sc individually. Power allocation of the transmitter (TR) between the carriers (C) is carried out in a manner determined by the computing module (10). 3. The service zone (2) according to claim 1 or 2, wherein the service zone (2) is determined in the sector Sc with respect to the attenuation thresholds (S, S2), and the first service zone (21) determines The pixels with attenuation lower than the first predetermined threshold S1 are grouped together, and the at least one second service zone 22, 23 has attenuation of the transmit / receive radio signal propagation with the first predetermined threshold S1. And grouping pixels that are between a predetermined maximum attenuation (Max) together. The method according to any one of claims 1 to 3, A list d21 of sectors Sc and the available power characteristics of these sectors; A matrix of propagation attenuation d30 for each sector; A matrix of traffic distribution d41; A coefficient of use indicative of the traffic amount d42; Specification of the number of carriers per sector d22; A matching rule d23 for associating a carrier with the transmit amplifier; Planned to be used for at least one convergence function (TEMP) used to prove that the power adjustment corresponds in particular to obtaining a maximum for the sum of the traffic processing capabilities of the carrier C of all sectors Sc. An initial step (40) to set a parameter such as a prediction parameter (d5). 5. The data as claimed in any one of claims 1 to 4, wherein the data indicative of the amount and distribution of traffic in the network comprises a measure of the quantity and quality of the subscriber traffic on the network. A traffic distribution map made through the data processing system 1 through the use of data representing traffic and data representing a geographic area, wherein the measurement corresponds to at least one predetermined time slot and at least one The network traffic distribution map is data representing the selection of at least one geographical region and the traffic corresponding to the selected geographical region and the predetermined time slots through the interaction means 3 between the user and the data processing system 1. Obtained after the search of the system of the data, associated with each transmitter , The power control method to be processed by the coverage of the treatment system 1 to generate the data shown. 6. The data according to claim 5, wherein the data representative of the traffic in the radio communication network (N) is provided by the counter means (4) and at least one operation by the extraction and table means (15) of the data processing system (1). And data extracted from the repair center (OMC). 7. The calculating step (41) according to claim 5 or 6, wherein the assigning step (42) of allocating a carrier to the service area (2) calculates a traffic distribution in an area corresponding to the coverage of the network (N). This traffic distribution calculation step 41 uses data distribution maps to predict traffic in each pixel, and also indicates data (d) indicating transmit / receive radio attenuation for each sector Sc. ), Considering the attenuation between the transmitter and receiver in the sector under consideration and the probability of allocation to the sector and the reception level of adjacent sectors with respect to the received field. 8. The method of claim 7, wherein the calculating of traffic distribution step (41) comprises calculating a cumulative distribution function of traffic to be processed with respect to the level of propagation attenuation in each sector (Sc) under consideration. 9. The allocation step 42 of any one of the preceding claims, wherein the assigning step 42 of allocating a carrier to the service area 2 comprises, for at least one of the sectors Sc, the total traffic TF to be processed. And the determination of the number N of sufficient carriers (C) allows the capacity of all carriers in the sector to handle the total traffic (TF). 10. The method according to any one of claims 1 to 9, wherein the frequency adjustment step 45 applies an interference constraint between carriers C, which includes the calculation of the compatibility matrix between all carriers C in all cells. A power adjustment method, which is processed by a calculation step for calculating. 11. The power adjustment step 45 for any of the carriers C, according to one of the claims 2 to 10, for all sectors Sc, the traffic of the carrier C of the sectors Sc. Between a first criterion corresponding to obtaining a maximum for the sum of the processing capacities and a second criterion corresponding to obtaining a minimum variance of traffic processing capacities individually provided by different carriers C in each sector Sc. And a first convergence prediction step (46). 12. The method according to claim 11, wherein following the calculating step, a calculating step 47 is performed to calculate a new frequency constraint resulting from the power adjustment, and then a second prediction step of predicting the convergence between the first and second criteria ( 48) is performed. 13. A third prediction step (50) according to claim 12, wherein the third prediction step (50) for predicting the convergence between the first criterion and the second criterion is performed immediately after a new calculation step 49 of the service zone 2 of each carrier C. And the new calculation step (49) takes into account the variation resulting from the power adjustment, in particular. 14. A method according to any one of claims 11 to 13, wherein at least one of said convergence functions (TEMP) in a form corresponding to the difference between a first value representing said first criterion and a second value representing a second criterion. And a comparison of the variation in the difference with an allowable threshold that should not be exceeded so that convergence remains in an acceptable state. 15. The method according to claim 14, wherein repetition R1 of the transmission output shared between carriers C in one and the same sector Sc is allowed in the first prediction step 46 of convergence between the first criterion and the second criterion. The power adjustment method triggered when the threshold is exceeded. 16. The repetition (R) of steps (43, 44) for calculating interference constraints and frequency adjustment between carriers (C) according to claim 14 or 15 comprises: a second of convergence between the first criterion and the second criterion; The power adjustment method triggered when the allowable threshold is exceeded in the prediction step 48. 17. The iteration R3 of any of claims 14 to 16, wherein the iteration R3 of the allocating step 42 for allocating carriers for the service area 2 is based on the convergence between the first and second criteria. The power adjustment method triggered when the allowable threshold is exceeded in the three prediction step 50. The characteristics of the data d1, the network sector Sc, and the transmitter TR representing the computing module 10 and the geographical area divided into a plurality of dots or pixels 301, 302, 303 according to the division of the network. A storage means 11 for storing data d2, data d3 indicating transmission / reception radio attenuation for each sector Sc, and data d4 indicating traffic amount and distribution of the network. 18. A data processing system 1 for carrying out the method according to any one of the preceding claims, wherein the data processing system 1 is for selecting each transmission sector Sc associated with the transmitter TR. Selecting means 12, the computing module 10, Storing the total sector traffic TF to be processed in the sector Sc into N shared traffic (TF / N) in N complementary service zones 2 determined with respect to radio attenuation. Using data (d1, d2, d3, d4) stored in the means (11), associate the carriers (C, C2, CN-1, CN) of the transmitter with the service area (2); A predetermined frequency f1, f2, f3 is associated with each service zone 21, 22, 23 so that different carriers C used in one sector Sc are respectively associated with a single service zone of the sector Sc. An associating means for associating, The data processing system 13 means for adjusting the transmit power of each carrier C in relation to the sharing of transmit power, determined by the computing module 10, between the carriers of one and the same sector Sc. Data processing system). The computing module 10 according to claim 18, wherein the computing module 10 is, according to the first criterion, a maximum value for the sum of the traffic processing capacities of the carriers C of all the sectors Sc, and, according to the second criterion, the sector Sc. Power of the transmitter TR between the carriers C of one and the same sector Sc using an optimal program suitable to obtain a minimum variance of the traffic processing capacity provided by the different carriers C). The prediction parameter d5 stored in the storage means 11 is used to determine the sharing, and the prediction parameter d5 stored in the storage means 11 is used in the storage means 11 used by the computing module 10 of the transmitter TR between the carriers C. A data processing system that enables optimized sharing of power. 20. The apparatus according to claim 18 or 19, wherein the associating means is arranged taking into account the attenuation thresholds S1 and S2 to determine the service area 2 of the sector Sc, wherein the associating means is configured to transmit and receive radio signal propagation Pixels with attenuation lower than the first predetermined threshold S1 of the first service zone 21, and attenuation of the transmit / receive radio signal propagation in at least the second service zones 22, 23 are such that the first threshold S1. ) And grouping pixels that are between a predetermined maximum attenuation (Max) together. 21. The system according to any one of claims 18 to 20, wherein the second memory 14 comprises data representing traffic data in the network for at least one predetermined time slot, wherein the system further comprises: Means for interaction 3 between a user and the system 1, connected to selection means 12 for selecting and displaying at least one said geographical area, Overlapping means for superimposing data representing the traffic over the selected geographic area in a predetermined time slot to form at least one traffic distribution map represented by the interaction means 3, Extraction and tableing means for extracting and tableing a series of measurements with respect to geographic area and time slots, using data provided by counting means 4 and derived from at least one operational and repair center (OMC) A data processing system comprising 15.

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